fix(tracing): Make `method` required in `transactionSampling` type (#4657)
fix(tracing): Make `method` required in `transactionSampling` type (#4657)

Though every transaction should have `transactionSampling` metadata, we mark the property as optional because we add it after the transaction is created, in the process of computing a sampling decision for it. Once `transactionSampling` exists, however, it should always have a `method` property.
getsentry/raven-js,getsentry/raven-js,getsentry/raven-js,getsentry/raven-js